Wireless device

ABSTRACT

According to an embodiment, a wireless device includes an interposer, a semiconductor chip, electrodes, and a slot antenna. The interposer includes conductive layers disposed at least at a side of a component mounting surface and a side of a reverse surface opposite to the component mounting surface. The semiconductor chip is mounted on the component mounting surface and includes a built-in transceiving circuit. The electrodes are disposed in a conductive layer disposed at the side of the reverse surface of the interposer so as to be electrically connected to an outside of the wireless device. At least a portion of the slot antenna is disposed in at least one of the conductive layers of the interposer. A shortest distance between an end in a width direction of the slot antenna and the electrodes is smaller than a sum of a minimum line width and a minimum line space of the interposer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2017-019953, filed on Feb. 6, 2017; theentire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a wireless device.

BACKGROUND

Conventionally, a method is known for having a slot antenna built into asemiconductor package in which a semiconductor chip is mounted on aninterposer. Moreover, in order to add a shielding function to thesemiconductor package, a technique for implementing a module with abuilt-in antenna has been proposed in which the surface of an sealingresin for sealing the semiconductor chip is covered using a conductivefilm; and a slot antenna is provided to extend from the conductive filmmeant for the shielding purpose, to a conductive layer of theinterposer.

Generally, a slot antenna is configured as a non-conductive portionsurrounded by conductive portions having ground potential. For example,a slot antenna is provided by forming a slit in a conductive layerhaving ground potential. In order to give an excellent radiationcharacteristic to the slot antenna, it is necessary that the slotantenna has a certain width. As a result, the space required for theslot antenna including the conductor pattern becomes relatively large.On the other hand, the conductive layers of the interposer have a highwiring density attributed to the wiring such as signal wiring and powersupply wiring. Hence, in the case of providing the slot antenna in aconductive layer of the interposer, it is difficult in the conventionaltechnology to achieve downsizing of the interposer while maintaining theradiation characteristic of the slot antenna. Hence, there is a demandfor improvement in that regard.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the external appearance of a wirelessdevice according to a first embodiment;

FIG. 2 is a cross-sectional view of the cross-section that runs alongA-A line illustrated in FIG. 1 and that is viewed from the Y directionillustrated in FIG. 1;

FIG. 3 is a planar view of an interposer when viewed from the reversesurface side;

FIG. 4 is a diagram illustrating an R1 portion, which is illustrated inFIG. 3, in an enlarged manner;

FIG. 5 is a diagram illustrating a comparative example;

FIG. 6 is a planar view of the interposer according to a firstmodification when viewed from the component mounting surface side;

FIG. 7 is a diagram illustrating an R2 portion, which is illustrated inFIG. 6, in an enlarged manner;

FIG. 8 is a planar view of the interposer according to a secondmodification when viewed from the reverse surface side;

FIG. 9 is a diagram illustrating an R3 portion, which is illustrated inFIG. 8, in an enlarged manner;

FIG. 10 is a planar view of the interposer according to a thirdmodification when viewed from the reverse surface side;

FIG. 11 is a planar view, when viewed from the reverse surface side, ofthe interposer of a wireless device according to a second embodiment;and

FIG. 12 is a diagram illustrating an R4 portion, which is illustrated inFIG. 11, in an enlarged manner.

DETAILED DESCRIPTION

According to an embodiment, a wireless device includes an interposer, asemiconductor chip, a plurality of electrodes, and a slot antenna. Theinterposer includes conductive layers disposed at least at a side ofsurface mounting components and a side of a reverse surface which isopposite to the surface mounting component. The semiconductor chip ismounted on the component mounting surface of the interposer and includesa built-in transceiving circuit. The electrodes are disposed in aconductive layer disposed at the side of the reverse surface of theinterposer so as to be electrically connected to an outside of thewireless device. At least a portion of the slot antenna is disposed inat least one of the conductive layers of the interposer. A shortestdistance between an end in a width direction of the slot antenna and theplurality of electrodes is smaller than a sum of a minimum line widthand a minimum line space of the interposer.

Embodiments of a wireless device are described below in detail withreference to the accompanying drawings. In the following explanation,the constituent elements having identical functions are referred to bythe same reference numerals, and the redundant explanation is notrepeated.

FIRST EMBODIMENT

Firstly, explained below with reference to FIGS. 1 to 5 is a wirelessdevice 100A according to a first embodiment. FIG. 1 is a perspectiveview of the external appearance of the wireless device 100A according tothe first embodiment. FIG. 2 is a cross-sectional view of thecross-section that runs along A-A line illustrated in FIG. 1 and that isviewed from the Y direction illustrated in FIG. 1. FIG. 3 is a planarview of an interposer 101 when viewed from the reverse surface side.FIG. 4 is a diagram illustrating an R1 portion, which is illustrated inFIG. 3, in an enlarged manner. FIG. 5 is a diagram illustrating acomparative example.

The wireless device 100A according to the first embodiment is configuredin the following manner: electronic components such as a semiconductorchip 102, a chip capacitor 103, and a crystal oscillator 104 that aremounted on the interposer 101 are sealed using a sealing resin 105; andthe surfaces of the sealing resin 105 and the side surfaces of theinterposer 101 are covered by a conductive film 106. The wireless device100A having such a configuration is called a semiconductor package or asemiconductor module with a shielding function. Meanwhile, the wirelessdevice 100A can also be configured without using the sealing resin 105and the conductive film 106. Moreover, only the semiconductor chip 102can be mounted as the electronic component on the interposer 101.

The interposer 101 is a substrate obtained by forming a plurality ofconductive layers on an insulating base material using a metal such ascopper; and functions as a linking member for connecting the electroniccomponents, such as the semiconductor chip 102, mounted thereon to alarger circuit board on which the wireless device 100A is mounted. Theinterposer 101 includes conductive layers disposed at least at a side ofa component mounting surface, on which the electronic components such asthe semiconductor chip 102 are mounted, and at a side of a reversesurface (i.e., a surface to face the circuit board) which is opposite tothe component mounting surface. Alternatively, the interposer 101 canhave a multilayered structure in which one or more conductive layers arefurther disposed in between the two conductive layers mentioned above.

In the conductive layer disposed at the side of the component mountingsurface of the interposer 101, a wiring pattern 107 is disposed to whichthe electronic components such as the semiconductor chip 102 areconnected. Moreover, in the conductive layer disposed at the side of thereverse surface of the interposer 101, for example, a plurality ofelectrodes 108 are disposed, which are electrically connected to theoutside of the wireless device 100A, such as to the circuit board, viasolder balls 110. The electrodes 108 include electrodes used forcommunicating signals with the circuit board (also including electrodesused for applying the power-supply voltage) and includes electrodeshaving ground potential; and are connected to the wiring pattern 107disposed at the side of the component mounting surface of the interposer101, via conductive via holes that are formed in a penetrating manner inthe thickness direction of the interposer 101. In the conductive layersof the interposer 101, at the positions where the wiring pattern 107 andthe electrodes 108 are not disposed, a solder resist 109 is applied toachieve electrical insulation.

The semiconductor chip 102 has a metallic pattern of copper, aluminum,or gold formed on the inside or on the surface layer of a semiconductorsubstrate made of a material such as silicon, silicon germanium, galliumarsenide, or gallium nitride; and has a built-in transceiving circuitfor transmitting and receiving signals. The semiconductor chip 102 ismounted on the component mounting surface of the interposer 101; and iselectrically connected to the wiring pattern 107, which is disposed atthe side of the component mounting surface, via bonding wires or bumps.

Alternatively, the semiconductor chip 102 can be configured as a chipsize package (CSP). Meanwhile, in FIG. 2, although it is illustratedthat a single semiconductor chip 102 is mounted on the interposer 101,it is also possible to have a plurality of semiconductor chips 102mounted on the interposer 101. In that case, the semiconductor chips 102either can be stacked or can be horizontally arranged.

The sealing resin 105 is made of, for example, a thermosetting moldingcompound having epoxy resin as the base with silica filler addedthereto; and is placed on the component mounting surface of theinterposer 101 for the purpose of protecting the electronic componentssuch as the semiconductor chip 102 mounted on the component mountingsurface of the interposer 101, and thus seals the electronic componentssuch as the semiconductor chip 102. Herein, the sealing resin 105 is anexample of an insulator used for sealing the electronic components suchas the semiconductor chip 102. However, the insulator is not limited toresin, and some other insulating material can alternatively be used.

The conductive film 106 is either made of metal with high conductivitysuch as copper, silver or conductive paste that is a mixture of a metalsuch as silver and an insulating material such as epoxy resin; and isformed as a film for covering the surfaces (the outside surfaces) of thesealing resin 105 and the side surfaces of the interposer 101. Thus, inthe wireless device 100A according to the first embodiment, the wholecircumference of the interposer 101, excluding the reverse surfacethereof, is covered by the conductive film 106. In the presentspecification, the surface of the conductive film 106 facing thecomponent mounting surface of the interposer 101 is called the principalsurface portion of the conductive film 106. Moreover, the surfaces ofthe conductive film 106 facing the side surfaces of the interposer 101are called the side surface portions of the conductive film 106.

Meanwhile, although not illustrated in the drawings, in between thesealing resin 105 and the conductive film 106, an underlayer made ofstainless-steel or titanium is formed with the aim of preventingabrasion of the conductive film 106. Moreover, on the surface of theconductive film 106, a protective layer made of stainless steel ortitanium is formed with the aim of preventing oxidation or corrosion.

The conductive film 106 has a shielding function by which thehigh-frequency electromagnetic waves (in the range of few tens of MHz tofew GHz) that are generated primarily from the semiconductor chip 102are prevented from leaking radiation noise to the outside of thewireless device 100A. The shielding effectiveness attributed to theconductive film 106 is dependent on the sheet resistance obtained bydividing the resistivity of the conductive film 106 by the thicknessthereof. In order to reproducibly prevent the radiation noise leakage,it is desirable that the conductive film 106 have the sheet resistanceto be equal to or smaller than 0.5 Ω.

Moreover, the conductive film 106 is electrically connected to aconductive portion having ground potential in one of the conductivelayers of the interposer 101. That is, since the conductive film 106covers not only the surfaces of the sealing resin 105 but also the sidesurfaces of the interposer 101, it makes contact with a conductiveportion having ground potential on the side surface of the interposer101 and gets electrically connected to the conductive portion. As aresult of a low-resistance connection of the conductive film 106 to theconductive portion having ground potential in the interposer 101, apotent shielding effectiveness can be achieved.

In the wireless device 100A according to the first embodiment, a singleslot antenna 120 is disposed across the principal surface portion of theconductive film 106, the side surface portion of the conductive film106, and the conductive layer disposed at side of the reverse surface ofthe interposer 101. The slot antenna 120 represents a slit-likeinsulating portion surrounded by the conductive portion having groundpotential. In the wireless device 100A according to the firstembodiment, the insulating portion formed by cutting a slit from theprincipal surface portion of the conductive film 106 over to the sidesurface portion thereof is in continuation with the insulating portiondisposed in the conductive layer at the side of the reverse surface ofthe interposer 101, to constitute a single slot antenna 120. The totallength of the slot antenna 120, that is, the length (slot length) fromone end of the slot antenna 120 in the principal surface portion of theconductive film 106 to the other end of the slot antenna 120 in theconductive layer disposed at the side of the reverse surface of theinterposer 101 is set to be approximately equal to the half wavelengthof the desired frequency used for communication by the wireless device100A.

Moreover, in the wireless device 100A according to the first embodiment,in the conductive layer at the side of the component mounting surface ofthe interposer 101, an antenna feeder 140 (see FIG. 3) connected to thesemiconductor chip 102 is disposed in an intersecting manner with theinsulating portion (a part of the slot antenna 120) in the conductivelayer at the side of the reverse surface of the interposer 101. Whenelectromagnetic-field-coupling-type power feeding is received from theantenna feeder 140, the slot antenna 120 becomes able to radiate orreceive electromagnetic waves of the desired frequency in an efficientmanner.

As illustrated in FIG. 3, a part of the slot antenna 120, which isdisposed in the conductive layer at the side of the reverse surface ofthe interposer 101, is formed of a insulating portion between aconductor pattern 130, which has ground potential and which is disposedat a distance from the side surface of the interposer 101, and the sidesurface portion of the conductive film 106. That is, regarding the slotantenna 120 in the conductive layer disposed at the side of the reversesurface of the interposer 101, one end in the width direction makescontact with the conductor pattern 130 and the other end in the widthdirection makes contact with the side surface portion of the conductivefilm 106.

With such a configuration of the slot antenna 120 in the conductivelayer disposed at the side of the reverse surface of the interposer 101,the space occupied by the conductor pattern 130 can be reduced ascompared to the case in which a slit is formed in the conductor pattern130 and is treated as a part of the slot antenna 120. The interposer 101has a high wiring density attributed to the wiring such as signal wiringand power supply wiring. For that reason, if a large space is occupiedby the conductor pattern 130 as required for disposing the slot antenna120, then it leads to an increase in size of the interposer 101. Hence,using the side surface portion of the conductive film 106 to form a partof the slot antenna 120 is helpful in achieving downsizing of theinterposer 101 and eventually achieving downsizing of the wirelessdevice 100A.

In the conductive layer disposed at the side of the reverse surface ofthe interposer 101, a plurality of electrodes 108 are disposed thatinclude electrodes used for communicating signals with the outside ofthe wireless device 100A (i.e., with the circuit board mentioned above)(hereinafter, such electrodes are called signal pins) and includeselectrodes having ground potential (hereinafter, called ground pins).With respect to the size and the arrangement of the electrodes 108 inthe interposer 101, there is the standard of, for example, the JointElectron Device Council (JEDEC). In order to manufacture the wirelessdevice 100A at low cost, it is desirable to use the interposer 101having the size and the arrangement of the electrodes 108 that conformto a standard.

In the interposer 101 having the size and the arrangement of theelectrodes 108 that conform to a standard; for example, as illustratedin FIG. 4, a distance L1 from the side surface of the interposer 101 tothe center of the electrodes 108 that are disposed in the vicinity tothe side surface is a defined value, as well a radius L2 of theelectrodes 108 is a defined value. Thus, in the case in which the slotantenna 120 in the conductive layer disposed at the side of the reversesurface of the interposer 101 is to be configured using the insulatingportion between the conductor pattern 130 and the side surface portionof the conductive film 106; the slot antenna 120 needs to be disposedwithin a distance L3 that is obtained by subtracting the defined valueL2 from the defined value L1.

As a comparative example, consider a case in which the electrodes 108that are positioned in the vicinity of the slot antenna 120 areallocated as signal pins. In that case, as illustrated in FIG. 5, theconductor pattern 130, which has ground potential and which makescontact with one end in the width direction of the slot antenna 120,needs to be disposed at a distance from the electrodes 108 positioned inthe vicinity of the slot antenna 120. Thus, the conductor pattern 130 isdisposed at the side surface side of the interposer 101 and requires, atthe minimum, a space equivalent to the sum of a minimum line width L4and a minimum line space L5 of the interposer 101. As a result, theshortest distance between an end in the width direction of the slotantenna 120 and the electrodes 108 becomes equal to or greater than thesum of the minimum line width L4 and the minimum line space L5 (equal toor greater than L4+L5) of the interposer 101. For that reason, the widthof the slot antenna 120 is limited to a size L6 that is obtained bysubtracting the values L4 and L5 from the value L3.

In this way, in the comparative example, the width of the slot antenna120 is limited, and there is concern about a decline in the radiationcharacteristic of the slot antenna 120. Moreover, when downsizing of theinterposer 101 is attempted, the width of the slot antenna 120 becomesfurther shorter, and the decline in the radiation characteristic becomesprominent.

In contrast, in the wireless device 100A according to the firstembodiment, the electrodes 108 that are positioned in the vicinity ofthe slot antenna 120 are allocated as ground pins. As a result, asillustrated in FIGS. 3 and 4, the conductor pattern 130, which hasground potential and which makes contact with one end in the widthdirection of the slot antenna 120, can be disposed in an overlappingmanner with the electrodes 108 positioned in the vicinity of the slotantenna 120. That is, the electrodes 108 positioned in the vicinity ofthe slot antenna 120 can double as a part of the conductor pattern 130having ground potential.

Thus, in the wireless device 100A according to the first embodiment,unlike in the comparative example, the space equivalent to the sum ofthe minimum line width L4 and the minimum line space L5 (i.e.,equivalent to L4+L5) of the interposer 101 need not be secured inbetween the electrodes 108 positioned in the vicinity of the slotantenna 120 and the slot antenna 120. That is, the shortest distancebetween the an end in the width direction of the slot antenna 120 andthe electrodes 108 can be set to be smaller than the sum of the minimumline width L4 and the minimum line space L5 (i.e., smaller than L4+L5)of the interposer 101; and the width of the slot antenna 120 can beincreased by the equivalent amount and the radiation characteristicthereof can be enhanced. Moreover, downsizing of the interposer 101 canbe achieved while maintaining the radiation characteristic of the slotantenna 120.

The wireless device 100A according to the first embodiment describedabove is configured as, for example, a package or a module having theball grid array (BGA) structure in which terminals formed by the solderballs 110 are disposed on the reverse surface of the interposer 101.Alternatively, the wireless device 100A can be configured as a packageor a module having land grid array (LGA) structure in which theelectrodes 108 disposed at the side of the reverse surface of theinterposer 101 are used as terminals, without disposing terminals of thesolder balls 110. In the case of a BGA structure, the opening of thesolder mask 109 often has a smaller diameter than the diameter of theelectrodes 108, thereby resulting in an over-resist configuration. Incontrast, in the case of an LGA structure, the opening of the soldermask 109 often has a greater diameter than the diameter of theelectrodes 108, thereby resulting in a clearance-resist configuration.Meanwhile, in FIGS. 1 to 4, although the wireless device 100A isillustrated to have a quadrangular planar shape, the outer shape of thewireless device 100A is not limited to this example, and it is possibleto have the wireless device 100A in various shapes.

As described above, in the wireless device 100A according to the firstembodiment, the shortest distance between an end in the width directionof the slot antenna 120, which is disposed in the conductive layerdisposed at the side of the reverse surface of the interposer 101, andthe electrodes 108, which are disposed in the conductive layer disposedat the side of the reverse surface of the interposer 101, is smallerthan the sum of the minimum line width and the minimum line space of theinterposer 101. Hence, the slot antenna 120 can be disposed in anefficient manner in the conductive layer disposed at the side of thereverse surface of the interposer 101, and downsizing of the interposer101 can be achieved while sufficiently securing the width of the slotantenna 120 and maintaining the radiation characteristic thereof.

Moreover, in the wireless device 100A according to the first embodiment,the single slot antenna 120 is disposed across the principal surfaceportion of the conductive film 106, the side surface portion of theconductive film 106, and the conductive layer disposed at the side ofthe reverse surface of the interposer 101. Hence, the slot antenna 120having a large slot length can be disposed while achieving downsizing ofthe interposer 101, and thus an antenna of a relatively low frequencycan be mounted.

Furthermore, in the wireless device 100A according to the firstembodiment, the insulating portion between the conductor pattern 130,which has ground potential and which is disposed at a distance from theside surface of the interposer 101, and the side surface portion of theconductive film 106 constitutes the slot antenna 120 that is disposed inthe conductive layer disposed at the side of the reverse surface of theinterposer 101. As a result, as compared to the case in which a slit isformed in the conductor pattern 130 and is treated as the slot antenna120, the space occupied by the conductor pattern 130 can be reduced.That gives an advantage while downsizing the interposer 101.

First Modification

In the wireless device 100A according to the first embodiment, a part ofthe slot antenna 120 is disposed in the conductive layer disposed at theside of the reverse surface of the interposer 101. However, theconductive layer in which a part of the slot antenna 120 is to bedisposed is not limited to the conductive layer disposed at the side ofthe reverse surface. Alternatively, a part of the slot antenna 120 canbe disposed in the conductive layer disposed at the side of thecomponent mounting surface of the interposer 101, or a part of the slotantenna 120 can be disposed in not only the conductive layer disposed atthe side of the component mounting surface of the interposer 101 butalso the conductive layer disposed at the side of the reverse surface ofthe interposer 101. Meanwhile, in the case of using the interposer 101having a multilayered structure in which a separate layer (anintermediate layer) is formed between the component mounting surface andthe reverse surface, a part of the slot antenna 120 can be disposed inthe intermediate layer.

FIGS. 6 and 7 are diagrams for explaining an example in which a part ofthe slot antenna 120 is disposed in the conductive layer disposed at theside of the component mounting surface of the interposer 101. FIG. 6 isa planar view of the interposer 101 according to the first modificationwhen viewed from the component mounting surface side. FIG. 7 is adiagram illustrating an R2 portion, which is illustrated in FIG. 6, inan enlarged manner. Meanwhile, in FIG. 6, the wiring pattern 107, whichis connected to the electronic components such as the semiconductor chip102, is not illustrated.

In the case of disposing a part of the slot antenna 120 in theconductive layer formed at the side of the component mounting surface ofthe interposer 101; for example, as illustrated in FIGS. 6 and 7, theconductor pattern 130 having ground potential is disposed at theconductive layer formed at the side of the component mounting surfacebut at a distance from the side surface of the interposer 101, and iselectrically connected to the side surface portion of the conductivefilm 106. Then, the insulating portion between the conductor pattern130, which has ground potential and which is disposed in the conductivelayer formed at the side of the component mounting surface of theinterposer 101, and the side surface portion of the conductive film 106is set to constitute a part of the slot antenna 120. That is, regardingthe slot antenna 120 that is disposed in the conductive layer formed atthe side of the component mounting surface of the interposer 101; oneend in the width direction makes contact with the conductor pattern 130,and the other end in the width direction makes contact with the sidesurface portion of the conductive film 106.

Moreover, in the conductive layer formed at the side of the componentmounting surface of the interposer 101, the antenna feeder 140 connectedto the semiconductor chip 102 is disposed in an intersecting manner withthe slot antenna 120. When coplanar power supply is received from theantenna feeder 140, the slot antenna 120 becomes able to radiate orreceive electromagnetic waves of the desired frequency in an efficientmanner. Meanwhile, as illustrated in FIG. 6, a part of the conductorpattern 130 is pulled around the antenna feeder 140. With that, such aportion can be made to function as side grounding.

In the first modification too, from among the electrodes 108 disposed inthe conductive layer formed at the side of the reverse surface of theinterposer 101, the electrodes 108 positioned in the vicinity of theslot antenna 120 are allocated as ground pins. As a result, theconductor pattern 130 can be disposed in such a manner that theorthogonal projection thereof overlaps with the electrodes 108 in thevicinity of the slot antenna 120; and the shortest distance between anend in the width direction of the slot antenna 120 and the electrodes108 can be set to be smaller than the sum of the minimum line width andthe minimum line space of the interposer 101. Thus, the width of theslot antenna 120 can be increased by the equivalent amount and theradiation characteristic thereof can be enhanced. Moreover, downsizingof the interposer 101 can be achieved while maintaining the radiationcharacteristic of the slot antenna 120.

As described above, in the first modification too, the shortest distancebetween the an end in the width direction of the slot antenna 120, whichis disposed in the conductive layer disposed at the side of thecomponent mounting surface of the interposer 101, and the electrodes108, which are disposed in the conductive layer formed at the side ofthe reverse surface of the interposer 101, can be set to be smaller thanthe sum of the minimum line width and the minimum line space of theinterposer 101. As a result, the slot antenna 120 can be disposed in anefficient manner on the conductive layer disposed at the side of thecomponent mounting surface of the interposer 101, and downsizing of theinterposer 101 can be achieved while sufficiently securing the width ofthe slot antenna 120 and maintaining the radiation characteristicthereof.

Second Modification

In the wireless device 100A described above, all electrodes 108positioned in the vicinity of the slot antenna 120 are allocated asground pins. Alternatively, the configuration can be such that some ofthe electrodes 108 positioned in the vicinity of the slot antenna 120are allocated as ground pins, and the width of the slot antenna 120 isincreased in the neighborhood of the electrodes 108 serving as groundpins.

FIGS. 8 and 9 are diagrams for explaining the second modification. FIG.8 is a planar view of the interposer 101 according to the secondmodification when viewed from the reverse surface side. FIG. 9 is adiagram illustrating an R3 portion, which is illustrated in FIG. 8, inan enlarged manner. In the second modification, some of the electrodes108 positioned in the vicinity of the slot antenna 120 are allocated asground pins and, as illustrated in FIGS. 8 and 9, a width W1 of the slotantenna 120 in the neighborhood of the electrodes 108 serving as groundpins (in FIG. 9, two electrodes 108 on the left-hand side) is increasedto be greater than a width W2 of the slot antenna 120 at otherpositions.

As described in the second modification, in the configuration in whichthe width of the slot antenna 120 is varied, it is desirable that thewidth is increased in the portion close to the stomach of the slotantenna 120 (i.e., the central part in the length direction in which thestanding waves increase in amplitude). As a result, while maintainingthe radiation characteristic of the slot antenna 120 at an excellentlevel, in the portion close to the nodes (i.e., the ends in the lengthdirection at which the standing waves decrease in amplitude), theelectrodes 108 positioned in the vicinity of the slot antenna 120 can beallocated as signal pins.

As described above, in the second modification, on the conductive layerformed at the side of the reverse surface of the interposer 101, a partof the slot antenna 120 is disposed from the neighborhood of theelectrodes 108 serving as ground pins to the neighborhood of theelectrodes 108 serving as signal pins, and the width of the slot antenna120 is varied. Hence, the number of electrodes 108 that can be used assignal pins can be increased while maintaining the radiationcharacteristic of the slot antenna 120 at an excellent level. With that,the number of electrodes 108 required in the interposer 101 can bereduced, thereby enabling achieving reduction in the cost of theinterposer 101.

Meanwhile, in the explanation given above, a part of the slot antenna120 is disposed in the conductive layer formed at the side of thereverse surface of the interposer 101. However, in an identical mannerto the first modification, a part of the slot antenna 120 can bedisposed in any one of the conductive layers, such as in the conductivelayer formed at the side of the component mounting surface of theinterposer 101.

Third Modification

In the wireless device 100A explained below, a part of the slot antenna120, which is disposed in a conductive layer of the interposer 101, isassumed to be linear in shape. Alternatively, a part of the slot antenna120 that is disposed in a conductive layer of the interposer 101 canhave various shapes. For example, as illustrated in FIG. 10, a part ofthe slot antenna 120 that is disposed in a conductive layer of theinterposer 101 can be bent and turned back midway along the lengthdirection, so that the slot antenna 120 having an adequate length can bedisposed in a conductive layer of the interposer 101 having limiteddimensions. Hence, an antenna of a relatively low frequency can bemounted while achieving downsizing of the interposer 101.

Fourth Modification

In the wireless device 100A explained above, the single slot antenna 120is disposed across the principal surface portion of the conductive film106, the side surface portion of the conductive film 106, and aconductive layer of the interposer 101. Alternatively, the configurationcan be such that the slot antenna 120 is disposed in only one of theconductive layers of the interposer 101.

SECOND EMBODIMENT

Explained below with reference to FIGS. 11 and 12 is a wireless device100B according to a second embodiment. FIG. 11 is a planar view, whenviewed from the reverse surface side, of the interposer 101 of thewireless device 100B according to the second embodiment. FIG. 12 is adiagram illustrating an R4 portion, which is illustrated in FIG. 11, inan enlarged manner. Meanwhile, a perspective view and a cross-sectionalview of the wireless device 100B according to the second embodiment areidentical to the respective views of the wireless device 100A accordingto the first embodiment (see FIGS. 1 and 2). Hence, those diagrams arenot illustrated.

The wireless device 100B according to the second embodiment has anidentical basic structure to that of the wireless device 100A accordingto the first embodiment. However, the slot antenna 120 that is disposedin a conductive layer of the interposer 101 has a differentconfiguration to that in the wireless device 100A according to the firstembodiment. That is, in the first embodiment, the insulating portionbetween the conductor pattern 130, which has ground potential and whichis disposed at a distance from the side surface of the interposer 101,and the side surface portion of the conductive film 106 constitutes theslot antenna 120 in a conductive layer of the interposer 101. Incontrast, in the second embodiment, as illustrated in FIGS. 11 and 12,the insulating portion between a first conductor pattern 130A, which hasground potential and which is disposed at a distance from the sidesurface of the interposer 101, and a comb-shaped second conductorpattern 130B, which is disposed adjacent to the side surface of theinterposer 101 and which is electrically connected to the side surfaceportion of the conductive film 106, constitute the slot antenna 120 in aconductive layer of the interposer 101.

The first conductor pattern 130A can have an identical configuration tothat of the conductor pattern 130 according to the first embodiment.That is, in the second embodiment too, in an identical manner to thefirst embodiment, from among a plurality of electrodes 108 disposed inthe conductive layer formed at the side of the reverse surface of theinterposer 101, the electrodes 108 positioned in the vicinity of theslot antenna 120 can be allocated as ground pins, so that the firstconductor pattern 130A that has ground potential and that makes contactwith one end in the width direction of the slot antenna 120 can bedisposed in an overlapping manner with the electrodes 108 positioned inthe vicinity of the slot antenna 120. That is, the electrodes 108positioned in the vicinity of the slot antenna 120 can double as a partof the first conductor pattern 130A having ground potential.

As illustrated in FIG. 12, the second conductor pattern 130B that makescontact with the other end in the width direction of the slot antenna120 is a comb-shaped conductor pattern in which a number of comb bladeportions 131, which extend from a base portion 132, have their leadingends placed in contact with the side surface portion of the conductivefilm 106. As a result of placing the leading ends of a number of combblade portions 131 in contact with the side surface portion of theconductive film 106, the second conductor pattern 130B gets electricallyconnected to the side surface portion of the conductive film 106.Moreover, as illustrated in FIG. 11, the second conductor pattern 130Bis connected to the first conductor pattern 130A via a link 133, and hasground potential in an identical manner to the first conductor pattern130A.

In the second embodiment too, in an identical manner to the firstembodiment, the first conductor pattern 130A that makes contact with oneend in the width direction of the slot antenna 120 can be disposed in anoverlapping manner with the electrodes 108 positioned in the vicinity ofthe slot antenna 120. Hence, the shortest distance between an end in thewidth direction of the slot antenna 120 and the electrodes 108 can beset to be smaller than the sum of the minimum line width and the minimumline space of the interposer 101; and the width of the slot antenna 120can be increased by the equivalent amount and the radiationcharacteristic thereof can be enhanced.

However, in the second embodiment, the second conductor pattern 130B ispresent in between the slot antenna 120, which is disposed in aconductive layer of the interposer 101, and the side surface portion ofthe conductive film 106. Hence, as compared to the first embodiment, thewidth of the slot antenna 120 gets limited by the amount equal to thesecond conductor pattern 130B. On the other hand, as a result ofdisposing the second conductor pattern 130B in between the slot antenna120 and the side surface portion of the conductive film 106, there is anadvantage of being able to effectively hold down an unfavorablesituation in which the misalignment occurring at the time of forming theconductor patterns (the first conductor pattern 130A and the secondconductor pattern 130B) in a conductive layer of the interposer 101causes variation in the width of the slot antenna 120 thereby resultingin changes in the characteristics thereof. That is, as is the case inthe second embodiment, when the non-conductive portion between the firstconductor pattern 130A and the second conductor pattern 130B constitutesthe slot antenna 120, even if there is some misalignment at the time offorming the conductor patterns, the width of the slot antenna 120 ismaintained constant. Hence, changes in the characteristics of the slotantenna 120, which are attributed to the variation in the width thereof,can be held down in an effective manner.

Moreover, in the second embodiment, because of the comb-like shape ofthe second conductor pattern 130B, in the dicing process for obtainingthe interposer 101, it becomes possible to hold down an unfavorablesituation in which the second conductor pattern 130B comes off.Generally, the interposer 101 is obtained by performing dicing(singulation) of a large-diameter substrate formed by arranging a numberof interposers 101. However, if the second conductor pattern 130B is asolid pattern, for example; then there is concern that, in the dicingprocess, the second conductor pattern 130B gets drawn into dicing bladesand comes off. In contrast, if the second conductor pattern 130B isconfigured to have the comb-like shape as explained above, there is adecrease in the amount of stress applied on the second conductor pattern130B in the dicing process, and the second conductor pattern 130B can beprevented from coming off. Moreover, in the second conductor pattern130B, the leading ends of a large number of comb blade portions 131 areplaced in contact with the side surface portion of conductive film 106as explained above. That enables reliable establishment of electricalconnection with the side surface of the conductive film 106.

Meanwhile, as explained in the first modification of the firstembodiment, in the second embodiment too, a part of the slot antenna 120need not be always disposed in the conductive layer formed at the sideof the reverse surface of the interposer 101, but can be disposed in anyone of the conductive layers such as the conductive layer at the side ofthe component mounting surface of the interposer 101. Moreover, asexplained in the second modification of the first embodiment, in thesecond embodiment too, the configuration can be such that the width ofthe slot antenna 120 disposed in a conductive layer of the interposer101 is varied. Furthermore, as explained in the third modification ofthe first embodiment, in the second embodiment too, the slot antenna 120disposed in a conductive layer of the interposer 101 can have variousshapes, such as being bent and turned back midway along the lengthdirection. Moreover, as explained in the fourth modification of thefirst embodiment, in the second embodiment too, the configuration can besuch that the slot antenna 120 is disposed in only one of the conductivelayers of the interposer 101.

According to at least one of the embodiments described above, downsizingof the interposer 101 can be achieved while maintaining the radiationcharacteristic of the slot antenna 120.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. A wireless device comprising: an interposer thatincludes conductive layers disposed at least at a side of a componentmounting surface and a side of a reverse surface which is opposite tothe component mounting surface; a semiconductor chip that is mounted onthe component mounting surface of the interposer and that includes abuilt-in transceiving circuit; a plurality of electrodes that aredisposed in a conductive layer disposed at the side of the reversesurface of the interposer so as to be electrically connected to anoutside of the wireless device; and a slot antenna, at least a portionof the slot antenna disposed in at least one of the conductive layers ofthe interposer, wherein a shortest distance between an end in a widthdirection of the slot antenna and the plurality of electrodes is smallerthan a sum of a minimum line width and a minimum line space of theinterposer.
 2. The device according to claim 1, further comprising: anon-conductor that is placed on the component mounting surface of theinterposer and that seals the semiconductor chip; and a conductive filmthat covers a surface of the non-conductor and a side surface of theinterposer, and that is electrically connected to at least one of theconductive layers of the interposer, wherein the slot antenna isdisposed across a principal surface portion of the conductive film whichfaces the component mounting surface of the interposer, a side surfaceportion of the conductive film which faces the side surface of theinterposer, and one of the conductive layers of the interposer.
 3. Thedevice according to claim 2, wherein the portion of the slot antennadisposed in at least one of the conductive layers of the interposer isformed of a insulating portion between a conductor pattern, which isformed in the at least one of the conductive layers and is separatedfrom the side surface of the interposer, and the side surface portion ofthe conductive film.
 4. The device according to claim 2, wherein theportion of the slot antenna disposed in at least one of the conductivelayers of the interposer is formed of a non-conductive portion between afirst conductor pattern, which is disposed in the at least one of theconductive layers and is separated from the side surface of theinterposer, and a comb-shaped second conductor pattern, which isdisposed in the at least one of the conductive layers and is adjacent tothe side surface of the interposer and which is electrically connectedto the side surface portion of the conductive film.
 5. The deviceaccording to claim 1, wherein the plurality of electrodes includes anelectrode used for communicating a signal with the outside of thewireless device and an electrode having a ground potential, and at leastthe portion of the slot antenna disposed in at least one of theconductive layers of the interposer is disposed from neighborhood of theelectrode having the ground potential to neighborhood of the electrodesused for communicating the signal, and a width of the slot antenna at aposition closest to the electrode having the ground potential is greaterthan a width at a position closest to the electrodes used forcommunicating the signal.